Abstract
Introduction: Any Frailty Index (FI) measures overall health. The FI-Lab employs common laboratory data and clinical measures to do so.
Objective: To examine how an FI-lab constructed from vital signs, laboratory tests, and electrocardiographic data is associated with in-patient admission and time to death. FI-Lab performance was compared with an FI from a Comprehensive Geriatric Assessment (FI-CGA), the Clinical Frailty Scale (CFS), and the Canadian Triage Acuity Scale (CTAS).
Methods: Participants were Emergency Department (ED) patients aged 65+ years referred to Internal Medicine, staffed by a geriatrician (KR). Fifty-seven FI-Lab variables were binarized (0 = no deficit; 1 = deficit) using standard normal ranges. Each FI was calculated as the fraction of items present as deficits. Age- and sex-adjusted Cox proportional hazard and logistic regression models were used to assess relationships with all-cause mortality, and in-patient admission, respectively.
Results: Of 928 patients, an FI-Lab was calculable in 780. Median age was 81 years (IQR:13); 53.9% were female. FI-Lab values ranged from 0.02–0.78 (mean: 0.42; standard deviation (SD) ±0.10). No significant sex differences were found [females (mean: 0.41±0.11) vs males (0.42±0.09; p=0.067)]. At 30 days, each 0.01 FI-Lab unit increase showed higher mortality hazard rate (HR) (95% confidence interval (CI):1.05 (1.03–1.07) and inpatient admission risk: Odds ratio (OR) 1.02 (1.00–1.04), as did the FI-CGA (1.02; 1.00-1.04) and CTAS (1.20; 0.83-1.75). Similar results held for inpatient admission, same for CTAS (1.18; 0.82-1.72). At one year, only the FI-lab and CFS significantly predicted mortality risk.
Conclusions: FI-Lab scores were associated with higher mortality rates and in-patient admission risk in older ED patients referred to Medicine. In acute care, the FI-Lab appears to integrate baseline frailty with illness severity. As such data often are routinely available, the FI-Lab might be an additional measure of frailty-related risk, potentially available in real time.
Comments
It seems that there is better evidence for CGA and triage in terms of admissions compared to FI lab. Illness severity seemed to be dictated by clinical judgement than by numbers !